actor-manager: Fix actor removal
actor-manager: Fix actor removal

Whoops, actor removal was trying to add instead of remove.

jonnylamb/mx,clutter-project/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,jonnylamb/mx,pwithnall/mx,jonnylamb/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx,pwithnall/mx